One‐Year Change in Walking Performance and Subsequent Mobility Loss and Mortality Rates in Peripheral Artery Disease: Longitudinal Data From the WALCS

BACKGROUND: Associations of 1‐year change in functional performance measures with subsequent mobility loss and mortality in people with lower extremity peripheral artery disease are unknown. METHODS AND RESULTS: Six‐minute walk and 4‐meter walking velocity (usual and fastest pace) were measured at baseline and 1 year later in 612 people with peripheral artery disease (mean age 71±9 years, 37% women). Participants were categorized into tertiles, based on 1‐year changes in walking measures. Cox proportional hazards models were used to examine associations between 1‐year change in each walking measure and subsequent mobility loss and mortality, respectively, adjusting for potential confounders. Compared with the best tertile, the worst tertile (ie, greatest decline) in 1‐year change in each performance measure was associated with higher rates of mobility loss: 6‐minute walk (Tertile 1 [T1] cumulative incidence rate [IR], 72/160; Tertile 3 [T3] IR, 47/160; hazard ratio [HR], 2.35; 95% CI, 1.47–3.74), usual‐paced 4‐meter walking velocity (T1 IR, 54/162; T3 IR, 57/162; HR, 2.21; 95% CI, 1.41–3.47), and fast‐paced 4‐meter walking velocity (T1 IR, 61/162; T3 IR, 58/162; HR, 1.81; 95% CI, 1.16–2.84). Compared with the best tertile, the worst tertiles in 1‐year change in 6‐minute walk (T1 IR, 66/163; T3 IR, 54/163; HR, 1.61; 95% CI, 1.07–2.43) and fast‐paced 4‐meter walking velocity (T1 IR, 63/166; T3 IR, 44/166; HR, 1.75; 95% CI, 1.16, 2.64) were associated with higher mortality. CONCLUSIONS: In people with peripheral artery disease, greater 1‐year decline in 6‐minute walk or 4‐meter walking velocity may help identify people with peripheral artery disease at highest risk for mobility loss and mortality.